Olefin conversion process for propylene and ethyle

2022-09-19
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The olefin conversion process for the production of propylene and ethylene

UOP and atofina company have industrialized the jointly developed olefin cracking process (OCP), which can convert C4 ~ C8 olefins into propylene and ethylene. This process can utilize C4 ~ C8 olefin streams from steam cracking units, catalytic cracking units and methanol conversion units to olefins. OCP process adopts fixed bed reactor with operating conditions of 500 ~ 600 ℃ and 0.1 ~ 0.5MPa. C4 ~ C8 olefins are cracked with the help of a special zeolite molecular sieve catalyst, which has a high propylene yield. The catalyst is regenerated by a switching reactor system. The research on the combination of OCP and naphtha cracking unit shows that for the relative naphtha flow rate, the propylene yield can be increased by 3%. As a result, the net propylene/ethylene ratio is 0.8. Such an increase in the combination determines that the investment in material processing is estimated to be $72million and the repayment period is 4 years. The validation device has been put into operation at the factory of atofina in Antwerp, Belgium. According to Sibur, further optimization of OCP process is under way

the Institute of resource chemistry, Tokyo University of technology, Japan, has developed a new catalytic reaction process for the direct synthesis of propylene from ethylene. The new process uses nickel ions of silicon nano porous bodies as catalysts, and uses solid catalysts to continuously convert raw ethylene into propylene and butane. At present, several petrochemical companies have participated in the development of this technology

the Chemical Resources Laboratory of Tokyo Institute of technology in Japan has verified the catalytic reaction process for the direct conversion of ethylene to propylene and butene. This process has high selectivity under atmospheric pressure. Using nickel based catalyst and MCM-41 nano porous silica as the carrier, MCM-41 is a regular 21? Nano porous structure. Ethylene and trace water react in a fixed bed reactor with the help of a nickel catalyst supported on mesoporous silica. The net reaction produces two moles of propylene from three moles of ethylene. The actual reaction mechanism is to complete two reaction steps on the same catalyst: two molecules of ethylene are first combined to form butene, and then butene is translocated with the third ethylene to form two propylene molecules. In the one-way conversion, the conversion rate of ethylene is about 53%. Propylene and butyl zigzag test are effective methods to detect the bending resistance of stainless steel and the coating, and the olefin selectivity is about 50% and 42% respectively. Butene can further increase the yield of propylene by reacting with ethylene. The next step is to test the microbial growth of perishable food and convert it into propylene with the same catalyst. This is the first reaction in the world to convert three ethylene molecules into two propylene molecules through catalytic reaction. Under normal pressure and 400 ℃, the conversion of ethylene is 68%, the selectivity of propylene is 49%, and the selectivity of butene is 42%. If necessary, this technology can be used to better balance the olefin yield of cracking unit. The combination of the new process and the existing ethylene cracking unit can increase propylene production, which is particularly useful when propylene demand is greater than ethylene demand. The laboratory has cooperated with industrial companies to industrialize the process

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